eChapters

COMMON FEATURES OF BIOLOGICAL MEMBRANES

Membranes are sheetlike, just a few molecules thick and form closed boundaries between cell compartments.

Membranes contain lipids and proteins, with small amounts of carbohydrayes linked to the lipids and proteins.

Lipids in membranes are small with hydrophobic and hydrophilic portions. Lipid bilayers provide a barrier to the diffusion of polar molecules.

Characteristic functions of membranes are mediated by specific proteins, serving as pumps, channels, receptors, energy transducers and enzymes.

Membrane components associate through noncovalent interactions.

Membranes are asymmetrical, with two sides of the membrane differing from each other.

Lipid and protein molecules often diffuse rapidly in the plane of the membrane.

Central transport of ions and molecules into and out of the cell.

Generate proton gradients for ATP production by oxidative phosphorylation.

Receptors bind extracellular signals and transduce the signal to cell interior.

Indifferent stage: Primordia are present for both sexes (gonads and mesonephric and paramesonephric ducts), although genetic sex is determined at fertilization.

Gonads : are structuarally indistinguishable prospective testis and ovaries. The first sign of gonadal development is a swelling called the gonadal ridge on the medial side of the middle part of the mesonephros. It enlarges due to arrival of primary germ cells. Cells of mesonephric tubules invade the ridge to form clusters and besides surround germ cells resulting in gonadal cords.

The primordial germ cells of these gonads arise from the endodermal cells of the yolk sac. These migrate to the gonadal ridge through the dorsal mesentry. Migration of primordial germ cells from the yolk sac endoderm into the gonadal ridges initiates testicular (if SRY gene is present) or ovarian development. The primordial germ cells form the sex cells, called gonadal blastema. The somatic blastema (non-germ cell) forms the other parenchymal elements of the gonads. The germ cells are capable of amoeboid-like movement.

Cardiovascular system consists of heart and blood vessels which include both arteries and veins. Blood vessels formation occurs in two stages i.e vasculogenesis and angiogenesis. Splanchnic mesodermal cells lining the yolk sac form clusters, referred to as blood islands. Vasculogenesis, the formation of blood vessels from blood islands of of Pander, commences during the third week of gestation in domestic animals first in yolk sac and later in the allantois.Development of blood vessels involves a complex series of events during which endothelial cells differentiate, proliferate, migrate and become organized into vascular network. Angiogenesis describes budding and sprouting of new vessels from existing vessels. This process a fundamental requirement for embryological development, continues postnatally.

Somites are derived from paraxial mesoderm and they are located lateral to the developing notochord and neural tube. During the third week of gestation in domestic animals, the outlines of somites first become visible and in the fifth week of gestation the somite formation is completed. Somites differentiate into sclerotome, myotome and dermatome. They form skeletal, muscular and dermal elements i.e, vertebral column, muscles and dermis respectively.

The connective tissue, cartilage and bone all differentiate from mesenchyme which arises chiefly from mesodermal somites and lateral layer of somatic mesoderm while connective tissue of alimentary canal and lower respiratory tract is derived from splanchnic mesoderm. Mesenchyme is a spongy meshwork composed of branching cells spaces between which are filled by ground substance. The supporting tissues, connective tissue, cartilage and bone are derivatives of mesenchyme in which ground substance is gelly like, stiff and firm respectively.

Introduction

The animal husbandry and agriculture are the major resource of income for the farmers and directly affects the economic conditions of farmers. Livestock sector plays a vital role for livelihood food security in India. Buffalo plays an important role in dairy industry and contribute 49 per cent of total milk production in India (BAHS, 2017). Murrah is one of the best buffalo breeds in the world and also widely used for up-gradation of non-descript buffaloes in India. Murrah buffalo have poor thermoregulation mechanism compared to other domestic ruminants in tropical countries and are more prone to heat stress due to very less sweat glands, jet black colour and thin hairs on body surface (Das et al., 1999; Khongdee et al., 2013) which reduce the ability of cutaneous evaporation and largely responsible for its low productivity and consequently reducing the reproductive efficiency (Gudev et al., 2007). India continues to be the largest milk producer in the world since 1997. Milk production has increased from 165.4 million tonnes (2016-17) to 176.4 million tonnes (2017-18) (DAHD, GOI). The demand for milk is increasing at a very fast pace due to exponential population growth and the gap in the production and supply is increasing. Out of 300 million bovines, only 88 million are in milk leaving large unproductive animals including 84 million males (19th Livestock census, 2012). If the gap of production and supply is to be bridged, the large number of constraints that affect reproductive efficiency and productivity of dairy animals must be addressed effectively. One important factor that can contribute to the productivity of animals is qualitative production and quantitative adequacy of semen doses for A.I.

Introduction

Livestock plays an important role in the sustainable livelihood of poor people of rain-fed agro-ecosystem, because of inherent risk involved in the crop farming due to uncertainty of rainfall and occurrence of recurrent droughts. They provide income and increased economic stability, and often the most important “cash crops” in small-scale mixed farming systems. Livestock sector in India is highly livelihood intensive and most rural households own livestock of one species or the other and earn supplementary incomes from them. Livestock holding is less iniquitous than land holding and income from livestock is more equitably distributed. The sector contributes 25.6 per cent of the value of output at current prices of total value of output in agriculture, fishing & forestry sector and in GDP, it was 4.11% in 2012-13 (19^th livestock census, 2012) therefore, development of the livestock sector is the critical pathway to rural prosperity

As per the 19^th livestock census, the total livestock population consisting of Cattle, Buffalo, Sheep, Goat, Pig, Horses & Ponies, Mules, Donkeys, Camels, Mithun and Yak in the country is 512.05 million numbers in 2012. The total Bovine population (Cattle, Buffalo, Mithun and Yak) is 299.9 million numbers in 2012 which shows a decline of 1.57% over previous census. In percentage basis distribution of livestock were: 37.28% were cattle, 21.23% buffaloes, 12.71% sheep, 26.40% goats and 2.01% pigs. The corresponding figures as per the 18th Livestock Census were 37.58%, 19.89%, 13.50%, 26.53% and 2.10%. The number of milch animals (in-milk and dry) in cows and buffaloes has increased from 111.09 million to 118.59 million, an increase of 6.75%. The number of animals in milk in cows and buffaloes has increased from 77.04 million to 80.52 million showing a growth of 4.51%. The Female Cattle (Cows) Population has increased by 6.52% over the previous census (2007) and the total number of female cattle in 2012 is 122.9 million numbers. The Female Buffalo population has increased by 7.99% over the previous census and the total number of female buffalo is 92.5 million numbers in 2012. The buffalo population has increased from 105.3 million to 108.7 million showing a growth of 3.19%. The total sheep in the country is 65.06 million numbers in 2012, declined by about 9.07% over census 2007. The Goat population has declined by 3.82% over the previous census and the total Goat in the country is 135.17 million numbers in 2012. The total poultry population in the country has increased by 12.39% over the previous census and the total poultry in the country is 729.2 million numbers in 2012. The total number of animals in milk in the country is 116.77 Million numbers.

Lipids are a class of organic compounds composed of hydrogen (H), carbon (C), and oxygen (O) atoms. These classes of biomolecules come together to create the fundamental building blocks that shape and govern the structure and functionality of living cells. The term lipid was used by the German biochemist Wilhem Bloor in 1943. Lipids are heterogeneous groups of substances that are insoluble in polar (water) and soluble in non-polar (ether, benzene, and chloroform) solvents. Lipids are the esters of fatty acids and their derivatives. Lipids play a crucial role in both the plant and animal domains. They are widely distributed in plants, but lipids are primarily stored in animal adipose tissues.

Classification of lipids

Lipids are classified into four different groups, as shown below:

1. Simple lipids

2. Complex lipids

3. Derived lipids and

4. Miscellaneous lipids

Amino acids are organic molecules made up of carbon (C), hydrogen (H), oxygen (O), and nitrogen (N). However, sulfur (S) and selenium (Se) are also found in some cases. Amino acids are essential organic compounds that come together to create proteins, thus making them the fundamental building blocks of proteins. These biomolecules play vital roles in various biological and chemical processes within the human body and are essential for the growth and development of an individual.

Amino acids consist of an acidic group (-COOH), a basic group (-NH2 ), and a side chain (R) or a hydrogen (H) atom, all bonded to the carbon atom. The features of amino acids are due to the side chain because they differ only in their side chain. All amino acids have the same basic structure except proline, which has a cyclic structure.

Various forms of amino acids like alpha (α), beta (β), gamma (γ) or delta (σ) form are found. The position of the amino group (-NH2 ) determines the form of the amino acid, i.e., if the NH2 group is attached to the α-carbon, it is called α-amino acid; if β-carbon, it is called β-amino acid, and so on. Mostly, α-Amino acids are found as the numbering of amino acids is done from the carboxylic group (-COOH).

Nucleic acids are complex, chain-like polymers consisting of nucleotides as their monomers. Due to this characteristic, they are often referred to as polynucleotides. The largest molecules present in the biological system are nucleic acids. The two main types of nucleic acids are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). The bulk of DNA is confined to the nucleus and some cell organelles like mitochondria and chloroplast. RNA is found in both the nucleus and cytoplasm. In 1869, Johannes Friedrich Miescher isolated a substance from the nuclei of the pus cell (leukocytes). The extracted material was named nuclein, which contained an unusually large amount of phosphorus; in addition to proteins, and devoid of sulfur. Richard Altman later named the nuclein as nucleic acid. These organic molecules are found in living cells and play a crucial role in transmitting genetic information from one generation to another.

Nucleotides

Nucleotides serve as the fundamental constituents of nucleic acids. Nucleotides have flat planar and heterocyclic origin. Nucleotides are small molecules composed of three components:

1. Nitrogenous base,

2. Pentose sugar and

3. Phosphate group.

The extreme weather events being experienced at a greater frequency now a days are due to accelerated climate change caused mostly due to global warming. Global warming is basically a change in the climatic conditions of the Earth, brought about by a considerable rise in the near-surface temperature of the planet. Earth’s surface and the troposphere become warmer due to absorption of infrared radiation emitted by the Earth’s surface by Green House Gases(GHGs). The important green house gases include carbon dioxide(CO₂),methane(CH₄) nitrous oxide(N₂O), chloro-?uoro-carbons(CFCs), ozone(O₃) and water vapour(H₂O). Various climate models predict major changes in our weather patterns, environment, and way of life in absence of efforts for substantial reductions in GHG emissions. The CO₂ gas concentration of atmosphere has increased to 385 ppm as against the normal concentration of 300 ppm. The atmosphere contains only 1 % of the total global carbon pool. The undesirable changes can be reversed by increasing soil and eco system carbon pools, increasing mean resident time(MRT) of sequestered carbon and decreasing GHG emission to atmosphere.

Introduction

Carbohydrates are the most common source of energy for all living cells, which, in presence of light, are formed by the green plants from CO₂ and water during photosynthesis. It canbe said that ‘light’ is theultimatesourceof energyrequired for all livingcells.Glucose,a monosaccharide,plays a centralroleincarbohydrate metabolismin all plants, animals and manymicroorganisms. Glucose is derived from the polysaccharides (starch, glycogen) and non-carbohydrate sources (amino acids, glycerols, etc.) during metabolism and ultimately converted either into carbondioxide and water orotherintermediateproducts.Complete oxidation of glucose to CO₂ and water provides ~2,840 kJ/mol energy. The other monosaccharides such as fructose, galactose, mannose, etc. are also important molecules in carbohydrate metabolism.

Stomach

Horse

The stomach of horse is a simple stomach. It is ‘J’ shaped sac with its right part very much shorter than the left part. It is situated in the dorsal part of the abdominal cavity behind the diaphragm and liver mainly to the left of the median line. The parietal surface faces craniad and dorsad and to the left. It is related to the diaphragm and liver. The visceral surface faces caudad and ventrad and to the right. It is related to the small intestine and colon. Its lesser curvature is short and the greater curvature is extensive. The left extremity is called the saccus caecus. It lies ventral to the sixteenth or seventeenth rib. It is related to pancreas and terminal part of greater colon caudally and to the base of the spleen laterally. The right extremity is the pylorus. It is smaller and is continued by duodenum. The stomach is fastened by several ligaments which include the gastro-phrenic ligament, the gastro- pancreatic ligament, the greater omentum, the lesser omentum and the gastro-splenic ligament. The capacity of the equine stomach is about 8 to 15 liters.

The wall of the stomach consists of four coats, the serous, muscular, submucous and the mucous. The mucous membrane is clearly divided into two parts by sinuous ridge called the margo plicatus. The part which is towards the left extremity is nonglandular while that towards the right extremity is glandular.

Introduction

Nutrition, a basic human need, is a critical part of health and development. Nutrition can be defined as the intake of food, deliberated in relation to the body’s dietary needs. On one hand, good nutrition – an adequate, well balanced diet combined with regular physical activity – is a foundation of good health, whereas,poor nutritionleads toreducedproductivity,impairedmental andphysical development, increased susceptibility to disease, and reducedimmunity. According to WHO, under-nutrition, together with vitamin and mineral deficiencies accounts for one-third of all child deaths and impairs healthy development and lifelong productivity. At the same time, sedentary lifestyles, demographic shifts, urbanization and the liberalization of markets have steered the world population to being overweight along with risk of chronic diseases like hypertension, dyslipidemia, type 2 diabetes, coronaryheart disease, stroke, etc.; thus, resulting in a double burden of malnutrition.

To address this dual burden of malnutrition, individuals needaccess to sufficient and good quality food; but focussing solely on food security is unlikely to solve the problem of global malnutrition. The challenges of malnutrition cannot be solvedjustbyincreasingfoodproductioninordertoimprove healthand nutritional status of the population. To resolve such challenges, awareness about food choices for optimal health plays a pivotal role among population.

Human nutrition is the science of understanding food; its component; intake; and how it is related to health, growth, development and diseases. Human nutrition involves the study of ingestion, digestion, absorption and assimilation of the nutrients; their metabolic functions, deficiency or excess disease as well as their regulation through several factors such as choosing particular food components/nutraceuticals or physical activity.

Introduction

Digestion may be defined as the hydrolytic process carried out by various enzymes for breaking down complex food components such as proteins, fats and carbohydrates into simpler molecules like amino acids, fatty acids and monosaccharides, respectively. Whereas, absorption may be defined as the movement ofthese simple soluble digested food componentsalongwithvitamins, minerals and water from gastrointestinal track into the circulatory system.

The process of digestion starts from oral cavity (mouth) and ends at large intestineincluding tongue, teeth, jaws,secretions from salivaryglands (parotids, sub maxillary or submandibular and sublingual glands), pharynx, esophagus, stomach, small intestine and digestive enzymes secreted from pancreas and liver.

Introduction
Cooperation is an extensive wonder. Biologists refer this term communication as mutually advantageous interplays that occur with things of the unchanging species. Cooperation in animals performs to occur generally for direct benefit or middle from two points relatives. Spending opportunity and possessions helping a related individual grant permission initially appear destructive to an animal’s chances of endurance but is actually
advantageous over the enduring. However, few researchers, like Tim Clutton-Brock, assert that communication service is a more intricate process. They state that helpers can sustain more direct, and less unintended, gains from assisting possible choice than it is usually stated. These gains include guardianship from predatoriness and increased generative appropriateness. Furthermore, they claim that cooperation concede possibility not only
be an interplay between two things but can be part of the more extensive aim of uniting populations. A generalized birth of progress that normalizes competition as a big method casts unity as a paradox, faraway in a confuse place survival is calculated in agreements of costs and benefits, following the market rule of self-addition. Prominent biologists, such as Charles Darwin, E. O. Wilson, and W. D. Hamilton, have erect the development of
cooperation spellbinding because evolutionary theory favors those who attain prominent supporter generative success while joint attitude often decreases the generative benefit of the player (the individual performing the helpful attitude).

Introduction

Greenhouse gases (GHGs) are the atmospheric trace gases which absorb and emit infra-red radiation and thereby trapping the heat radiated from the earth surface. The commonly known agriculturally important GHGs are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). The major anthropogenic sources of CO₂ emission in atmosphere are biosphere, burning of fossil fuels and land use changes in tropical forests. The atmospheric concentration of CO₂ has increased from 280 parts per million by volume (ppmv) in 1750 to 394 ppmv in 2012 and is currently increasing at the rate of 1.9 ppmv year-1 (NOAA, 2012). Atmospheric CH₄ concentration has increased from about 715 to 1826 parts per billion by volume (ppbv) in 2012 over the same period and is increasing at the rate of 7 ppbv year-1 (IPCC, 2007; EPA, 2013). Similarly, the atmospheric concentration of N₂O has increased from about 270 ppbv in 1750 to 325 ppbv and is increasing at the rate of 0.8 ppbv year-1 (IPCC, 2007; EPA, 2013).

The UN designation of 2013 as the International Year of Water Cooperation aptly demonstrates growing gap between water supply and demand. These symptoms, which are already visible in a few regions around India, are soon to assume a national proportion and may become permanent feature of the water sector in the country, unless suitable policies are adopted quickly to manage water demand and supply at different levels. Water demand is growing fast due to a rapid population growth and economic activity, but water supply is not growing at the same rate because of serious ûnancial and physical limits for supply augmentation. Water resources developed at present amount to about 680 km³, which constitutes 61% of the utilizable potential of 1122 km³. However, it is difficult to add supply beyond this level due to heavy costs, environmental concerns and interstate water conûicts. In contrast, the total demand for water is projected to reach 784–843 km3 by 2025 and 973–1180 km³ by 2050 (Ministry of Water Resources, 2000). Recent research studies predict that, if the demand– supply gap continues to increase, nine basins that have over four-ûfths of the total water use in India will face physical water scarcity by 2050 (see Amarasinghe et al., 2007). For a heavily populated, monsoon-dependent and rural-based country, such as India, water scarcity of this magnitude will not only lead to serious water conûicts among sectors and regions, but also have a devastating effect on the food and livelihood fronts.

Introduction
An animal’s asymmetry in aggression towards another species is commonly used to characterise its dominance. In other contexts, dominance describes people who emerge victorious from brief dyadic competitions. Most animal groups are arranged in a hierarchical fashion, whereby members at higher ranks have more access to resources and opportunity for procreation than members at lower ranks. Signals of Dominance: Acts or structures known as signals are employed by signalers to convey information to recipients in a way that elicits a response from them. This response usually has positive fitness consequences for both the signaler and the recipient. These signs don’t always have to be easy to see.
Communities vary in the hierarchical pattern of dominance. The most common kind of rank relationships are those in which there is a “alpha” who is better than all other members of the group, a “beta” who is better than all members except the “alpha,” and so on down the hierarchy to the lowest ranker who is under all others. Therefore, if powerful males may be arranged in a single sequence, the system is known as a simple and linear dominance hierarchy.
Concepts of Dominance Hierarchies
1. Establishing dominance
2. Maintaining dominance
Dominance Hierarchy Types
1. Statistical hierarchy
2. Confidence hierarchy
3. Assessment hierarchy

Introduction

Pastoralism involving rearing of different livestock species makes significant contributions to the economy of developing countries, both in terms of providing employment and income opportunities and in supplying nutrition to rural poor. Pastoralism generally has a mobile aspect, and movement of animal herds in search of fresh pastures and water is a key feature qualifying pastoralism. The term nomadic is used when mobility is high and in irregular patterns; transhumant when there are regular back-and-forth movements between relatively fixed locations; and sedentary for the rest. Pastoralists inhabit zones where the potential for crop cultivation is limited due to steep terrain, extreme temperatures and low and highly variable rainfall. Within this unpredictable, vulnerable and dynamic environment, they have developed successful mechanisms of adaptation to maintain an ecological balance between themselves and the natural environment. Thus, pastoralism is a successful strategy to support a population on less productive land that adapts well to the environment. Transhumance is the seasonal migration of livestock and pastoralists between higher and lower pastures.